Sauna Building Made Easy...

2. Sauna Location... Indoor Sauna or Outdoor Sauna - Don't feel restricted in the location you choose for your sauna - it's just as practical in your backyard or beside your swimming pool as it is indoors in your walk-in closet or basement, garage or recreation room. Although both indoor saunas and outdoor saunas are popular, there are benefits and disadvantages to each type. Outdoor saunas will cost more to install when you include the cost of running plumbing or electrical wiring to the sauna site as well as the added expense of building a protective outdoor sauna roof. The same pre-cut sauna kit will be used for your indoor sauna or outdoor sauna as you will be using the material in the pre-cut kit identically inside the framed enclosure.

Essential Reading: The Sauna Book, "The Art of Sauna Building"

5. Sauna Wall Framing...

Sauna Wall Framing - The stud frame for each sauna wall can be constructed on the floor outside the sauna. You need to build the sauna walls allowing for air intake and exhaust vents, the rough opening of 26"x75" for the sauna door as well as allowing for any windows in the sauna walls. When complete, the wall section is then raised and attached to the concrete floor with anchor bolts or concrete nails. A drop ceiling, framed with 2"x4" spaced every 16" is then added. The sauna ceiling height of 7' should not be exceeded. A sauna height greater than 84" will require a larger sauna heater in order to heat the space above the 84". The heat that will rise to fill the space above 84" will be a major inefficiency in sauna heating

Typical 5'x7' Sauna Plan

Typical Stud Framing for Horizontal T&G Material

6. Sauna Wiring & Insulation... Sauna Controls & Wiring - You will need to hire an electrician to install the electrical circuits for the sauna heater, sauna controls, thermostat and sauna lighting. While many sauna heaters have the controls built-in right on the bottom of the sauna heater, we recommend that the sauna controls be located on the outside of the sauna for convenient access. Deluxe sauna controls are a popular option from your sauna dealer (Great Saunas). The wiring needs to be rated for 90°C (194°F) and must be located along the cooler side of the sauna wall.

Building the Inside of the Sauna Specs

Sauna Foil Vapor Barrier - After the sauna wiring has been installed, install the aluminium foil vapor barrier and the insulation to keep the heat inside the sauna. A layer of special high temperature aluminium foil vapor barrier (with the shiny side facing inwards towards the sauna) must be used to prevent moisture from collecting in the sauna walls and also to reflect heat back into the sauna. As this special vapour barrier is very difficult to find from traditional building supply sources, you will probably buy it from a sauna supplier like Great Saunas.

Sauna Insulation - Saunas are usually insulated with conventional fiberglass insulation batts that come in 15" widths. The sauna insulation should be chosen according to its "R" value which defines its ability to keep heat in. An "R13" rating is fine for sauna walls while "R22" to "R26" is required in the sauna ceiling. We recommend that you use the same R13 for the ceiling and install two layers of the sauna insulation so they are laid in different directions.

7. Sauna Doors & Windows...

Sauna Door Sizes - Sauna doors always open out for safety reasons. A standard size sauna door measures 24"x72" to minimize the amount of heat lost when the sauna door opens. The sauna door should have a handle made of a matching wood and a non-metallic friction door catch. Pre-made sauna doors are available from sauna dealers and are highly recommended to building your own door from scratch. The changing sauna heat and humidity conditions can easily warp and bend a home made door. Factory made sauna doors are available with regular and full height windows. Great Saunas has 16 sauna door designs available. The most popular sauna door is the deluxe full window door as it lets in more light and adds to the feeling of spaciousness when using your sauna.

Sauna Windows - Windows can be installed in the walls but they should be made of single glazed tempered glass. Avoid double glazed glass units which often "fog up" from moisture collecting inside the panes of glass. Allow enough room in the window frame to allow the glass to expand slightly to prevent the glass from cracking when it heats up. Don't worry about any heat loss through a window in the sauna. Your heater will make up the heat in about 10 seconds.

8. Walls - T&G Wood Lining... Inside T&G Wood Lining - Interior sauna walls can be lined in a horizontal or vertical design using tongue and groove cedar boards of 1"x4" or 1"x5" nominal widths. Cedar boards should be attached using 1.5" rust-resistant galvanized nails angled at the base of the tongue of each board so the next board will fit over the tongue and the nail head to hide it from view.

Blindnailing & Countersinking Specs

Horizontal T&G is Best - The horizontal application of T&G cedar boards is highly recommended over the alternate and older style of vertical boards. Horizontal boards are much easier to install, they make the sauna room look larger and create a better seal of the tongue and groove.

The type of wood you choose for the interior of your sauna is subject to your own taste, but try not to use dark wood that gives the sauna a somber appearance inside. Generally, you will find that Western Red Cedar is the preferred wood for building a home sauna in North America because of its light colour, ability to absorb perspiration and odours and withstand the humidity changes of the traditional heat sauna while it releases a pleasant aroma inside the sauna room

Exterior Wall Lining - You will have a lot of flexibility in designing the exterior of your sauna because the exterior materials can be painted or stained. Exterior paneling can be the same wood as the interior or you may use another type of material such as wallboard, stone, brick, tile or regular 4x8 paneling. Remember to confirm your sauna wall thickness with your sauna dealer so you get the right size of door frame.

9. Sauna Benches...

Sauna Benches & Construction - After the interior T&G has been installed, it's time to build the sauna benches. The sauna bench material should consist of thick 2"x2", 2"x3" or 2"x4" cedar planks, clear of all knots and fastened with screws on the underside. Most sauna benches are arranged in a two-tier upper and lower bench layout that will allow you to enjoy cooler or warmer temperature levels. L-shaped sauna benches along two walls are usually found in larger sauna rooms, like the 6'x7' and 6'x8' as the sauna room is large enough for 4 sauna benches. Sauna sizes 5' x 7', 5' x 8' and 6' x 6' have enough room for only 1 L-bench along the side wall. This third sauna bench can be a top bench or a bottom bench depending on your preferences.

Sauna Bench Sizes - The sauna benches should be long enough to allow the bather to stretch out. Benches are usually built with an air space of one half inch between the bench planks to permit air to circulate through the bench. Lower level sauna benches should be installed about 18" above the sauna floor and upper tier sauna benches should be installed 46" from the ceiling to allow adequate head space. The top bench is usually installed 18" higher than the lower bench in a sauna room with a normal 7' ceiling height. In sauna rooms that are 5'x5', 5'x6', 5'x7' or larger, the top sauna bench is normally 20" wide and is quite comfortable for sitting or laying down. The bottom sauna bench is 17" wide making it strong enough to be the main step up to the top bench or to be able to support an overflow crowd of sauna bathers.

The sauna heater must be installed by a certified electrician and must be properly sized to heat your sauna room. If the heater is undersized, you will experience problems with the high-limit control tripping out. If the sauna heater is oversized, you will feel a searing, burning type of heat from the powerful heater that is not pleasant for sauna bathers. A quick rule of thumb for calculating the size of the sauna heater for a sauna room that is 7' high is to divide the cubic feet of the sauna room by 50 to give you the needed kilowatt size of a 240 volt sauna heater.

Wood Saunas - Wood burning sauna stoves are considered by sauna devotees to be the most natural way to heat a sauna even though they create more work in tending the fire and cleaning the ashes. These wood fired sauna stoves need 1 to 1.5 hours to heat the sauna (vs 25-30 minutes for most electric sauna heaters). It takes a little time to get a strong fire roaring in wood fired sauna stoves.

Personal Saunas - Small 110-volt electric sauna heaters are designed to seat one or two persons. Larger 220 volt heaters are required for all other saunas. Electric heaters range in size from 2 Kw to 18 Kw. The sauna heater size is calculated by by allowing 1 kilowatt (Kw) for every 45 or 50 cubic feet of sauna space.

Gas Sauna Heaters Are Expensive to Install - A gas sauna heater is an alternative to electric heaters. Gas is supplied to a burner in a sealed combustion chamber located underneath a tray of sauna rocks. A gas sauna heater is sized in BTU's (British Thermal Units), based on 1,000 BTU's for every 15 cubic feet of sauna space. If you decide to use a gas sauna heater, you will need to have gas lines installed to the sauna heater or have propane tanks located outside the sauna. The expense of the piping for propane or natural gas and the need to vent the gas through a regular chimney makes the gas sauna heater option quite expensive to install. The savings in the gas heating cost will never pay for the extra sauna installation costs.

Air Circulation Vents for the Sauna

11. Sauna Lighting... The Lighting in the sauna is essential to relaxation and enjoyment. A single light fixture in the sauna is sufficient with usually a 60 watt light bulb in it. The sauna light must have a heavy-duty glass globe and an aluminium base. A cheap shower light will not last in the heat of the sauna.If the fixture base is a cheap painted coating, the paint will eventually peel and become unsightly. Some sauna companies market sauna kits with 2 sauna lights.

That may look nice but just be sure to reduce the wattage size of the light bulbs. Some sauna builders are also placing their sauna lights under the top bench in order to keep the lighting nice and subdued. Be careful here, as you will have some very sharp shadows in the room. It would be a good idea to test out your sauna lighting plan first. In my first sauna, I used a 60 watt orange light bulb for a calming, relaxing effect. As I often had mixed company in my sauna, this helped any modest visitors to relax sooner and be more comfortable.

The location of the light is also very important as the sauna light should never be directly in your eyes or in your normal line of sight. Off to the side usually works. Also avoid a ceiling light fixture that will obstruct people coming and going from the sauna benches.

12. Sauna Vents & Air Circulation...

Sauna Vents & Venting - You will need sauna venting to create an air circulation system to keep the heat in the sauna distributed evenly and the air odour-free. Sauna venting (in the sauna) must include an intake vent near the floor under the sauna heater and an exhaust vent on the other side of the sauna room to create air movement, to distribute the heat evenly and to maintain the proper oxygen level in the sauna. The exhaust air at the outlet vent is quite dry so it will not add to the humidity level of your home.The air can now be re-directed anywhere. We recommend using a 3"x10" duct space as 30 square inches is adequate for good air flow. Air vents can be purchased separately. See Vents.

I've seen sauna companies build several sauna vents right in the sauna door. They may look like they will work but they only create air flow from one sauna vent to the next vent in the same area. These vents do not promote air movement in the sauna that will distribute the heat evenly. Traditional sauna building techniques call for a generous air space below the door so why even bother with a separate sauna vent in the door? The only time I could accept this design of sauna venting is when the sauna is constructed in an old fruit cellar and there is absolutely no way to build sauna vents in the concrete walls.

If the sauna vents cannot cut through the wall directly, build a hollow space inside the wall frame to serve as an air duct. You can then locate the sauna vent anywhere you need at the end of this venting space.

After your sauna has been installed and the heating equipment and sauna controls have been connected, it should be cleaned of all debris. Let the sauna run for two hours at 80 °C (180°F) to burn off the coatings on the new heater elements and to ensure that the sauna rocks won't crack later. If the high limit control on the heater trips out, just reset it, it will be ok in the future.

Have fun building your sauna!

12. Index to Sauna Terms on This Page...

Outdoor Sauna Plans - Section 2 Explains Outdoor Sauna Planning, Designing & Building
Our "how to build a sauna" section provides excellent info on making a heat sauna, similar to "how to make a sauna".

Building your own sauna is easy with help from Great Saunas Factory. We define: Sauna Construction, How to Build a Traditional Sauna, Build a Sauna, Build Sauna, Sauna Installation, Do It Yourself Sauna, Building a Sauna, How To Build Sauna, Homemade Sauna, Building Saunas, Make a Sauna, Making Saunas and Build Saunas. All of these terms describe Finnish traditional sauna building methods & techniques as well as sauna building secrets that we gathered during our 34 years building saunas. How to Build Your Own Sauna with a pre-cut sauna kit is a specialty at Great Saunas for DIY sauna builders.

An Excerpt from"The Art of Sauna Building" Section A.11 by Pertti Olavi Jalasjaa CLICK to Order the Book